1. Field of the Invention
The present invention relates generally to machine tools and more particularly to improvements in a tool bit and tool holder assembly which provides for a plurality of tool bit cutting positions while the tool bit holder is rotatably mounted in conventional commercially available machines such as a lathe.
2. Description of the Prior Art
This invention relates to the art of metal cutoff and particularly that type of metal cutoff wherein a rigid cutoff tool is advanced into the periphery of a rotating workpiece so as either to effectuate cutoff of a portion of the workpiece or to place a groove in the same as required.
With respect to the prior art holder, when a workpiece is to be treated in various locations or positions by the tool bit blade to perform the operation of shaping, facing, chamfering and the like, from different directions from the holder such as straight right or straight left and end right or end left the tool holder and insert must be replaced in the lathe machine with a separate tool holder and the respective insert for each position.
Another disadvantage of the prior art tool bit holder is that separate and individual tool holders must be used to provide for different center heights when mounted on the tool post of a lathe machine, for example.
The following U.S. Patents are believed to exemplify the present state of the art with respect to tool bit holders: U.S. Pat. Nos. 3,603,185; 3,815,454, 4,332,513; 4,599,923; 4,640,159.
While such prior art devices provide improvement in the areas intended, there still exists a need for a tool bit holder device which overcomes the disadvantages of the prior art while providing utility features which provide new and useful advantages and improvements not heretofore disclosed.
Accordingly, a principle desirable object of the present invention is to provide a new and improved tool bit holder device which overcomes the disadvantages of the prior art devices.
Another desirable object of the present invention is to provide a new and improved tool bit holder wherein the tool holder body permits a single blade to be mounted in different positions about the holder
A further desirable object of the present invention is to provide a tool bit holder shank which allows the tool bit holder to be positioned for different center heights.
A still further desirable object of the present invention is to provide a single tool bit holder which is constructed and arranged to provide various machining operations that cannot be performed by a conventional tool bit holder.
Another desirable object of the present invention is to provide a tool bit holder including the foregoing desirable objects which is simple in design, inexpensive to manufacture, rugged in construction, easy to use and efficient in operation.